1. Field of the Invention
The present invention relates to a clock down sensor, and more particularly to a clock down sensor used to monitor the transmission status of network.
2. Description of Related Art
At present, there are many types of signal sensors and so are their usages; they can generally be used on fire warning, guarding against burglar and measurement. The basic principle of theirs is to use a temperature, pressure or light sensing equipment to detect the change of temperature, pressure and light, and then, a detecting signal is emitted to use as a warning signal. In general, clock pulse signal detection function does not exist in a general transmission facility, therefore, when a data transmission is processed in an optical fiber or a general wire material, if disappearance of a pulse signal happens in the middle of the transmission due to oscillator or other elements failure, no warning is received in the system even if a whole transmission is terminated. Thus, time and transmission resource wastes are caused because it is unable to be detected and repaired immediately. Therefore, the existence of a clock down sensor is necessary in a signal transmission.